Flexible pixel element and signal distribution means

ABSTRACT

Discrete flexible pixel elements are hermetically sealed from the environment and comprise unitary, self-contained replaceable modules which enable efficient, economical production of large scale, free-form electronic displays, signs and lighting effects for outdoor use. The method and means for producing hermetically sealed discrete flexible pixel elements include encapsulation means, exterior casement means, and cable connector means.

CROSS REFERENCES TO RELATED APPLICATIONS

This application is a continuation-in-part of patent application Ser.No. 10/965,127 filed on Oct. 14, 2004 now abandoned, entitled “FlexiblePixel String Software and Method.”

This application claims priority from the earlier filed U.S. ProvisionalApplication No. 60/926,706 filed Apr. 27, 2007, entitled “Flexible PixelAssemblies for Mounting on Irregular Surfaces,” and is herebyincorporated into this application by reference as if fully set forthherein.

This application is related to U.S. utility patent application Ser. No.10/965,133 filed on Oct. 14, 2004, entitled “Flexible Pixel StringHardware and Method,” which is pending.

This application is also related to U.S. utility patent applicationentitled “Flexible Pixel Element Fabrication and Sealing Method”,application Ser. No. 11/895,424, filed concurrently herewith, a copy ofwhich is attached and the disclosure of which is incorporated byreference as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention teaches a discreet flexible pixel element for usein flexible pixel strings, a connection means for serially connecting aplurality of discreet flexible pixel elements into flexible pixelstrings, and a distribution means for distributing operating power,image data and control signals to a flexible pixel string, thereby toproduce visual display images and lighting effects for viewing by aviewing party or public. Flexible pixel strings may be used inelectronic display devices and signage and, more particularly, innon-rectilinear, non-planar electronic display devices having irregularshapes and surface features. Electronic displays having irregular shapesor surface features include channel letter displays, free-form logo anddesign displays; curved, round and cylindrical displays, and the like.Displays of this type often are mounted on large area surfaces, such asthe interior or exterior of buildings, where the intent is to complementthe surface architecture of the building by conforming to the buildingsurfaces. The discreet flexible pixel element, connection means, andsignal distribution means of the present invention enable efficient,economical production of large scale, direct view electronic displays,signage and lighting effects that are not restricted to rectilinear andplanar configuration, but may freely conform to irregular shapes andsurfaces.

2. Description of the Prior Art

Electronic display devices and electronic signage are known in the art.An electronic display device typically comprises a display board thatproduces visual images by means of a grid of small light-emittingelements such as incandescent bulbs, LEDs, or the like; data handlingand control means for managing transfer of digital image data fordisplay as visual images, and means for converting digital image datainto visual image data and display control signals to drivelight-emitting elements or pixels to produce visual images on anelectronic display board for viewing.

The graphical content that can be displayed on electronic displaydevices is technology-dependent and generally limited by thelight-emitting elements used to produce visual images. Early prior artelectronic display devices consisted of a matrix or grid of smalllight-emitting elements, such as incandescent bulbs, which were turnedon and off in simple patterns to produce text messages and primitivegraphic images for viewing. Continuing improvements in the art haveproduced electronic display devices that are increasingly larger inscale and more powerful with respect to the size, complexity andsophistication of visual images that can be displayed. Light-emittingdisplay technology also has become increasingly more sophisticated,progressing from monochrome incandescent and LED devices to videoquality components capable of producing near continuous-tone graphicaloutput, dynamic combinations of text and images, complex animations,recorded video sequences and live video streams.

Electronic display devices of irregular shape also are known in the art.One popular type of irregular shape electronic display device is channelletter signage, where large block letters with internal channels arefitted with light-emitting elements to produce signage and lightingeffects. Depending on the type of light-emitting elements used, as wellas the capabilities of the control means employed, early prior artchannel letter signs were capable of producing simple dynamic graphicaleffects such as flashing, rippling, scrolling and the like. The priorart provides for channel letter signs that can display video qualityimages and a variety of dynamic lighting effects.

The construction of prior art irregular shape electronic displaydevices, including channel letter signage, is typically accomplishedusing conventional rectangular-grid video components. However, such useof rectangular-grid video components is inelegant and wasteful inimplementation, while the end result often lacks the desired effect thatshaped video components can provide. Moreover, rectangular-grid videocomponents and control system means are inadequate for creating the typeof custom shaped electronic display devices that are becomingincreasingly popular. Custom shaped electronic displays may benon-rectilinear and non-planar (e.g., circular, cylindrical andspherical displays), making the use of rectangular-grid video componentsto produce custom shaped electronic displays difficult to execute andexpensive to produce. However, electronic display devices and signagethat use rectangular-grid video components are more easily repaired thanthose that use shaped video components, since rectangular-grid videocomponents are easily replaced when they fail or are damaged, whileshaped video components must be re-fabricated to match the failed ordamaged components.

Additional problems in the prior art result from limitations oftechnology used to distribute signals, such as operating power, imagedata and display control signals, to pixel elements ganged together inlarge scale displays and signage. In the prior art, pixel elementdriving circuits, such as LED drivers, typically reside on one or moreoff-board printed circuit boards (PCBs) within a remotely locateddisplay controller. Distribution of operating power, image data, anddisplay control signals to the pixel elements is accomplished by meansof lengthy power and signal cables. This means of supplying pixelelements with operating power, image data and control signals incursseveral disadvantages. First, power loss and signal degradation acrosslong run lengths of conductors limits the distance the off-board pixelelement driver PCBs can reside from the pixel elements they drive, thuslimiting the size of the electronic display device to the maximumconductor run length and restricting optimal placement of remote displaycontrollers. Second, limitations on the number of pixel elements thatcan be serviced by a single driver PCB requires the use of multipledriver PCBs to service a large plurality of pixel elements embodiedwithin large scale electronic displays and signage. Third, the use ofmultiple driver PCBs requires the concomitant use of expensive power andsignal cables to service the pixel elements. Finally, the multiplicityof driver PCBs, power cables and signal cables, in addition to the largeplurality of pixel elements inherent in the design of large scaleelectronic display devices and signage, creates a vulnerable designarchitecture having complex wiring with many connection points andpotential points of failure. Moreover, while the prior art provides forserial-connection of pixel elements in electronic display devices andsignage, the data transmission distance between pixel elements islimited to short distances and still requires a large number of powerand signal conductors to transmit operating power, image data andcontrol signals between pixel elements.

Another problem inherent in the prior art is means and methods toprotect a vulnerable design architecture having many potential points offailure and delicate electronic components, such as pixel elements anddrivers, from failure due to harsh environmental conditions andinclement weather, a particular problem with outdoor or exteriorelectronic displays and signage. In the prior art, pixel elements arecollectively sealed in protective enclosures to protect them from theelements. Not only does this add to the cost of already expensive largescale exterior electronic displays and signage, but producing enclosuresthat conform to irregular shaped surfaces can be a complex and costlyundertaking. Moreover, such an enclosure constitutes a single failurepoint, wherein any failure of the enclosure exposes all the connectionpoints and delicate electronic components contained therein to potentialfailure. Finally, collective enclosures are subject to over-heating fromboth internal and external sources including component power dissipationand solar radiation.

A solution to these and other problems is taught in patent applicationSer. No. 10/965,133 filed on Oct. 14, 2004, entitled “Flexible PixelString Hardware and Method,” pending, which teaches the use of flexiblepixel strings that can be conformably applied to fit irregular shapessurfaces, including non-rectilinear and non-planar shapes and surfaces,such as channel letter displays, and is hereby incorporated into thisapplication by reference as if fully set forth herein. A portion of thatteaching is the use of a plurality of discreet flexible pixel elementsthat can be connected in series by means of flexible connectors andwiring to produce a flexible pixel string that is conformable toirregular shapes and surfaces.

The present invention discloses further teaching of means and methodsoperative and efficacious in producing the aforesaid discreet flexiblepixel elements, including means of connecting said discreet flexiblepixel elements in series-connection to embody flexible pixel strings.The present invention also teaches signal distribution means to supplyoperating power, image data, and display control signals to discreetflexible pixel elements embodied within flexible pixel strings.

In summation, the prior art is generally dependent on conventionalmeans, such as rectangular-grid video components, to produce electronicdisplay devices and signage having advanced graphical capabilities thatalso can conform to irregular shapes and surfaces. As a result, designand production of such devices are slow and inefficient, productioncosts are prohibitive, and outcomes are often inelegant and failureprone. Clearly, a novel approach to address the aforesaid deficienciesof the prior art is needed to continue to satisfy public demand andthereby ensure continuing development of the art.

SUMMARY OF THE INVENTION

The general purpose of the present invention is to provide direct view,large scale electronic display devices and signage having advancedgraphical capabilities that can conform to irregular shapes andsurfaces. More specifically, the present invention embodies a discreetflexible pixel element that can be interchangeably connected in serieswith a plurality of like discreet flexible pixel elements to embody aflexible pixel string. Said discreet flexible pixel element may embody asingle light-emitting element, such as a solitary LED or incandescentbulb, or may embody a plurality of light-emitting elements, such as aplurality of red-green-blue (RGB) LEDs electronically connected withinsaid discreet flexible pixel element.

Said flexible pixel string may be one of a plurality of interchangeableflexible pixel strings that comprise a flexible pixel string array. Saidflexible pixel strings and said flexible pixel string arrays can beapplied conformably to irregular shaped and non-planar surfaces therebyto produce direct view, large scale, electronic display devices anddynamic electronic signage and lighting effects such as visual displays,architectural lighting, color effects lighting, channel letter lighting,and similar such applications. Said large scale electronic displaydevices, dynamic electronic signage and lighting effects may be appliedto interior and exterior surfaces of buildings, large conveyances andtransport vehicles such as ships and trucks, and similar large areasurfaces.

According to one embodiment of the present invention there is provided adiscreet flexible pixel element having at least one and preferably aplurality of on-board light-emitting elements or pixels. In a preferredembodiment of the present invention, said on-board light-emittingelements or pixels of said discreet flexible pixel element comprise aplurality of red, green and blue LED light-emitting pixel elements.

According to another embodiment of the present invention, there isprovided a discreet flexible pixel element having at least one andpreferably a plurality of on-board pixel element drivers for drivingsaid on-board light-emitting pixel elements. In a preferred embodimentof the present invention, said on-board pixel element drivers fordriving said on-board light-emitting pixel elements of said discreetflexible pixel element comprise a plurality of constant-drive LEDcurrent drivers that drive a plurality of red, green and blue LEDlight-emitting LED pixel elements.

According to still another embodiment of the present invention, aplurality of said discreet flexible pixel elements are connected inseries to comprise a flexible pixel string. In a preferred embodiment ofthe present invention, a plurality of said flexible pixel strings areapportioned into operative groups to comprise flexible pixel stringarrays, wherein each said flexible pixel string array embodying saidplurality of flexible pixel strings is driven by a line controller.

According to yet another embodiment of the present invention, saiddiscreet flexible pixel element comprises a non-unique, non-addressed,self-contained unit that is fully interchangeable with any other likeunit. In a preferred embodiment of the present invention, each saidinterchangeable discreet flexible pixel element has a single inputconnector having at least four input signal conductors and a singleoutput connector having at least four output signal conductors, whereinthe output connector of any given discreet flexible pixel element can beoperatively fitted and connected to the input connector of any othergiven discreet flexible pixel element thereby operatively to establishseries connection.

According to still another embodiment of the present invention, aplurality of said flexible pixel strings can be conformably applied to,or mounted on, irregular shapes and surfaces including non-rectilinearand non-planar surfaces such as channel letter displays, pillars, curvedwalls and the like to produce large scale electronic display devices anddynamic electronic signage and light effects.

According to still another embodiment of the present invention, there isprovided a display controller that operatively controls said discreetflexible pixel elements, and thereby said flexible pixel strings, todrive a plurality of light-emitting elements therein such as RGB LEDs,thereby to produce visual display output including light-generatedimages and lighting effects from electronic display devices and signage.In a preferred embodiment of the present invention, said displaycontroller embodies a signal distribution means whereby operating power,image data and control signals are operatively transmitted to aplurality of said discreet flexible pixel elements serially-connected bymeans of flexible cables or conductors.

According to yet another embodiment of the present invention, saiddisplay controller embodies image data conversion means that convertsconventional graphical image data created for matrix-grid type,rectilinear or planar electronic display devices into visual image dataand control signals corresponding to logical and spatial placement andposition of said discreet flexible pixel elements embodied within saidflexible pixel strings conformably applied to irregular shapes andsurfaces.

A significant aspect and feature of the present invention is that aplurality of discreet flexible pixel elements may be interchangeablyconnected in series to embody flexible pixel strings. Advantageously,said flexible pixel string requires only a single line driver to supplypower and signal requirements to service said plurality ofseries-connected discreet flexible pixel elements comprising saidflexible pixel string and the light-emitting pixel elements therein.

Another significant aspect and feature of the present invention is thatsaid flexible pixel strings can be apportioned into operative groups offlexible pixel string arrays. Advantageously, each said flexible pixelstring array can be driven by a remote line controller embodying aplurality of line drivers corresponding to the number of flexible pixelstrings contained within said flexible pixel string array, thus allowinggreater design freedom to conformably apply said flexible pixel stringarrays to irregular shapes and surfaces such as channel letter displaysand the like.

Yet another significant aspect and feature of the present invention isthat flexible pixel strings and flexible pixel string arrays can beconformably applied to, or mounted on, irregular shape and non-planarsurfaces, thereby advantageously to produce large scale electronicdisplay devices, dynamic electronic signage and lighting effectsefficiently and economically.

Yet another significant aspect and feature of the present invention isthat each discreet flexible pixel element embodies on-boardlight-emitting pixel elements and on-board pixel element drivers,advantageously reducing some of the limitations of off-board pixelelement drivers such as power loss and signal degradation and enablingmeans to produce discreet, interchangeable flexible pixel elements.

Yet another significant aspect and feature of the present invention isthat each discreet flexible pixel element embodies one input connectorwith one input power conductor and no more than four input data andcontrol signal conductors and one output connector with one output powerconductor and no more than four output data and control signalconductors, thereby advantageously to reduce the number of connectorsand conductors to the minimum required to operatively provisionseries-connected discreet flexible pixel elements with operating power,image data and control signals.

A further significant aspect and feature of the present invention isthat each discreet flexible pixel element comprises a non-unique,self-contained unit that is fully interchangeable with any other likeunit. Advantageously, any given discreet flexible pixel element iseasily replaced with any other like discreet flexible pixel element whennecessary due to damage or failure, since the signal distribution meansof the present invention obviates any requirement for uniqueconfiguration, identification or addressing of said discreet flexiblepixel elements. Also advantageously, said discreet flexible pixelelements can be replaced while power to the electronic display device orelectronic sign is maintained.

Yet a further significant aspect and feature of the present invention isa display controller that embodies signal distribution means wherebyoperating power, image data and display control signals are transmittedserially to a plurality of said discreet flexible pixel elementsconnected in series by means of flexible cables embodying one inputconnector having one input power conductor and no more than four inputsignal conductors and one output connector having one output powerconductor and no more than four output signal conductors, thusadvantageously reducing the number of electrical connections, the lengthof power and signal cables, and the number of conductors needed tooperatively supply said discreet flexible pixel elements and thelight-emitting pixel elements therein with operating power, image dataand control signals, thereby reducing the number of potential failurepoints.

Yet a further significant aspect and feature of the present invention isa display controller that embodies an image data translator and pixelarray configuration table that convert conventional graphical image datacreated for use with matrix-grid, rectilinear and planar electronicdisplays into visual image data and display control signalscorresponding to irregular shape, non-rectilinear and non-planarelectronic display devices that embody said discreet flexible pixelelements, thereby advantageously to supply said discreet flexible pixelelements with requisite visual image data and display control signals.Also advantageously, said image data translator and pixel arrayconfiguration table eliminate any requirement for addressing orconfiguration means to uniquely identify placement or position of saiddiscreet flexible pixel elements.

Having thus described embodiments of the present invention and set forthsignificant aspects and features of the present invention, it is theprincipal object of the present invention to provide a discreet flexiblepixel element, a connection means for connecting a plurality of saiddiscreet flexible pixel elements in series to embody flexible pixelstrings, a conversion means to convert graphical image data from arectilinear, planar format to visual image data corresponding to thelogical and spatial positions of a plurality of said discreet flexiblepixel elements within a plurality of said flexible pixel stringsconformably applied to irregular shapes and surfaces, and a signaldistribution means for transmitting said converted visual image data,operating power and control signal to said discreet flexible pixelelements within said flexible pixel strings, thereby to produce visualdisplay images and lighting effects for viewing by a viewing party orpublic.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects of the present invention and many of the attendantadvantages of the present invention will be readily appreciated as thesame becomes better understood by reference to the following detaileddescription when considered in connection with the accompanyingdrawings, in which like reference numerals designate like partsthroughout the figures thereof and wherein:

FIG. 1 is an isometric view of the interchangeable discreet flexiblepixel element of the present invention;

FIG. 2 is a simplified connection diagram depicting a plurality ofdiscreet flexible pixel elements in series-connection to embody flexiblepixel strings apportioned into operative groups to embody flexible pixelstring arrays;

FIG. 3 is a general block diagram depicting a display system embodying adisplay controller, one or more line controllers, a plurality ofseries-connected discreet flexible pixel elements of the presentinvention, a plurality of flexible pixel strings, and a plurality offlexible pixel string arrays;

FIG. 4-A is a simplified circuit diagram depicting various electricalcomponents and circuit connections of the discreet flexible pixelelement of the present invention;

FIG. 4-B is a continuation of the simplified circuit diagram of FIG. 4-Adepicting additional electrical components and circuit connections ofthe discreet flexible pixel element of the present invention; and,

FIGS. 5-A and 5-B are a simplified connection diagram depictingseries-connection of a plurality of discreet flexible pixel elements andsignal paths between functional components thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is an isometric view of a preferred embodiment of discreetflexible pixel element 10 of the present invention. Discreet flexiblepixel element 10 embodies a printed circuit board 11, on which variouselectrical components (described hereinafter) are mechanically joined byoperative electrical connection, a plurality of light-emitting elements13 hermetically sealed within case 12, input connector 14, outputconnector 16 and flexible cables 18. Light-emitting elements 13illuminate when energized by on-board element drivers (not shown) toproduce visual output in the form of emitted light. In a preferredembodiment, light-emitting elements 13 comprise a plurality of red,green and blue (RGB) colored LEDs.

FIG. 2 is a simplified connection diagram depicting a plurality ofdiscreet flexible pixel elements 10 a-10 n connected in series to embodyflexible pixel string 20 a, wherein output connector 16 of a givendiscreet flexible pixel element 10 is operatively joined inseries-connection to input connector 14 of the next discreet flexiblepixel element 10 of flexible pixel string 20 a. FIG. 2 further depictsan operative grouping of flexible pixel strings 20 a-20 n apportioned toembody a flexible pixel string array 30.

FIG. 3 is a general block diagram depicting discreet flexible pixelelements 10 of the present invention as applied in a display system 50.Display system 50 embodies display controller 40 which transmits visualimage data and display control signals (not shown) via electronicinterface 34 to a plurality of line controllers 32 operatively enabledto transmit visual image data and display control signals to a pluralityof flexible pixel strings 20 embodying flexible pixel string arrays 30,which can conform to irregular shapes and surfaces in the production oflarge scale electronic display devices, as heretofore described.

Display controller 40 comprises operating system 42, output imagetranslator 44, and pixel array configuration table 46. Displaycontroller 40 operatively executes operating system 42 and output imagetranslator 44 to convert graphical image data from a source format,typically created for use with grid-matrix and rectilinear displays andsignage, into visual image data and display control signalscorresponding to the logical and spatial locations of discreet flexiblepixel elements 10 conformably applied to irregular shapes and surfaces,as maintained within pixel array configuration table 46. Pixel arrayconfiguration table 46 maintains logical and spatial position data foreach discreet flexible pixel element 10 used in display system 50. Onceoutput image translator 44 converts graphical image data into visualimage data, display controller 40 transmits said visual image datatogether with display control signals to line controllers 32 viaelectronic interface 34. Line controllers 32 route said visual imagedata and display control signals to the appropriate flexible pixelstring 20.

Display controller 40 may be any commercially available device capableof operatively transmitting visual image data and display controlsignals to line controllers 32 via electronic interface 34 such as apersonal computer or workstation. Alternatively, display controller 40may be any proprietary device capable of operatively transmitting visualimage data and display control signals to line controllers 32 viaelectronic interface 34.

In a first preferred embodiment of display system 50, display controller40 comprises the Daktronics® VNet® Display Controller. Details ofhardware configuration, internal communications, protocols and operationof said first preferred embodiment are further described in U.S. Pat.No. 5,949,581 entitled Display System, filed Aug. 12, 1997, and U.S.Pat. No. 6,169,632 entitled Display System, filed Feb. 9, 2000. Bothpatents are assigned to the assignee of the present invention and arehereby incorporated into this application by reference thereto as iffully set forth herein. In a second preferred embodiment of displaysystem 50, display controller 40 comprises the Daktronics® Venus 7000®Display Controller. Details of hardware configuration, internalcommunications, protocols and operation of said second preferredembodiment are further described in U.S. Pat. No. 6,819,303, entitledcontrol system for an electronic sign (video display system), filed Aug.17, 1998, assigned to the assignee of the present invention, and thatpatent is hereby incorporated into this application by reference theretoas if fully set forth herein.

Those skilled in the art will apprehend that reference to the aforesaiddisplay controllers 40 shall not be considered limiting in scope of thetypes of display controllers 40 that may be embodied within displaysystem 50.

Line controller 32 receives visual image data from display controller 40via electronic interface 34, buffers it in internal memory (not shown)and routes it as required along with display control signals to flexiblepixel strings 20. Line controller 32 may be any commercially availabledevice operatively capable of receiving visual image data and displaycontrol signals from display controller 40 via electronic interface 34and transmitting same to flexible pixel strings 20. Alternatively, linecontroller 32 may be a proprietary device produced for the samepurposes. In a preferred embodiment, line controller 32 comprises theDaktronics® ProPixel® Line Controller.

FIG. 4-A and FIG. 4-B are simplified schematic diagrams depicting theinternal components of discreet flexible pixel element 10 of the presentinvention. Referring now to FIG. 4-A, input connector 14 provides inputsupply voltage +VCC IN 14 a and four input data and control signalsCLKIN 14 b (CLOCK IN), DATAIN 14 c (DATA IN), LATIN 14 d (LATCH IN), andOEIN 14 e (OUTPUT ENABLE IN). Only input supply voltage and four inputdata and control lines are needed to supply operating power, image dataand display control signals to operate discreet flexible pixel element10.

Constant-current driver 100 (hereinafter designated CCD 100) is asolid-state integrated circuit (IC) device that operatively drives RGBLEDs 60-80 in accordance with visual image data and display controlsignals (not shown) received from display controller 40 via electricalinterface 34 and line controller 32. CCD 100 is a three-channelconstant-current LED driver capable of producing a wide range of drivingcurrent levels for driving RGB LEDs 60-80 as appropriate to theiroperational power requirements. CCD 100 controls operation of RGB LEDs60-80 using a pulse-width-modulated (PWM) control method that allowsvery precise control of intensity and duration of illumination. Inoperation, CCD 100 performs ON/OFF switching of RGB LEDs 60-80 by colorgroup at specified current drive levels (modulating intensity ofillumination) and for specified time intervals (modulating duration ofillumination) in accordance with visual image data received from displaycontroller 40. Modulating the current drive levels to each group of RGBLEDs 60-80, in combination with modulating the time interval that eachgroup of RGB LEDs 60-80 is illuminated, produces various patterns andcolors of emitted light thereby producing visual display output andlight effects. CCD 100 also re-drives output supply voltage +VCC OUT 16a and output data and control signals CLKOUT 16 b (CLOCK OUT), DATAOUT16 c (DATAOUT), LATOUT 16 d (LATCH OUT), and OEOUT 16 e (OUTPUT ENABLEOUT) to output connector 16. Output connector 16 operatively connects toinput connector 14 of the next series-connected discreet flexible pixelelement 10 thereby to supply said next discreet flexible pixel element10 in flexible pixel string 20 with the requisite operating power, imagedata and display control signals. The power and data signals transmittedfrom CCD 100 via output connector 16 are received at input connector 14of said next series-connected discreet flexible pixel element 10 andthereby received by CCD 100 instant as input supply voltage +VCC IN 14 aand input data and control signals CLKIN 14 b (CLOCK IN), DATAIN 14 c(DATA IN), LATIN 14 d (LATCH IN), and OEIN 14 e (OUTPUT ENABLE IN).Series resistors 110 modulate the slew rate, or rate of change, ofoutput signals CLKOUT 16 b, DATAOUT 16 c, LATOUT 16 d, and OEOUT 16 e toreduce electronic emissions and improve signal integrity over longseries-connections of a plurality discreet pixel elements 10.

In a preferred embodiment, CCD 100 embodies the Allegro Microsystems,Inc. 3-Channel Constant-Current LED Driver with PWM Control, ModelA6280; the apparatus, processes, functions and characteristics of saidpreferred embodiment of CCD 100 as described in applications manual“A6280 3-Channel Constant-Current LED Driver with PWM Control (A6280-DSRev. 3)” provide a complete and detailed understanding of theapplication of said preferred embodiment and that document is herebyincorporated in its entirety by reference thereto.

Those skilled in the art will apprehend that the foregoing exposition,as well as other aspects and features of CCD 100 here unstated,including means and methods of IC device application and operational andfunctional details, are limiting neither in scope nor intent of thepresent invention. For example, the preferred embodiment heretoforedescribed teaches LED driver means that embody a 3-channel device (e.g.,CCD 100 of the preferred embodiment) that drives RGB LEDs 60-80 by colorgroups by channel. It will be obvious to those skilled in the art thatthe present invention anticipates LED driver means which embody a5-channel device that drives RGBCM (i.e., red, green, blue, cyan andmagenta color LEDs) by color groups by channel, as well as LED drivermeans which embody two 3-channel devices (e.g., two CCD 100 devices ofthe preferred embodiment) that drive RGBCAW (i.e., red, green, blue,cyan, amber, and white color LEDs) by color groups by channel, operatingby multiplexed control signal means thereof, or by patterned selectionof dissimilar color LEDs with reference to a universal color space(e.g., hue-saturation-brightness), as appropriate to the uses andfunctions of display system 50. These and other minor differences inapplication of IC devices and other electrical components, and thedistribution of data and control signal thereof, are anticipated hereinand therefore captured by the scope and intent of the present invention.

Red LEDs 60 a-60 h provide light-emitting elements of discreet flexiblepixel element 10 for emitting red colored light. Eight red LEDs 60 a-60h are shown, but any number of red LEDs 60 a-60 n may be used dependingon the configuration requirements of discreet flexible pixel element 10and the operational capabilities of LED driver means as embodied by CCD100.

Green LEDs 70 a-70 f provide light emitting elements of discreetflexible pixel element 10 for emitting green colored light. Six greenLEDs 70 a-70 f are shown, but any number of green LEDs 70 a-70 n may beused depending on the configuration requirements of discreet flexiblepixel element 10 and the operational capabilities of LED driver means asembodied by CCD 100.

Blue LEDs 80 a-80 f provide light emitting elements of discreet flexiblepixel element 10 for emitting blue colored light. Six blue LEDs 80 a-80f are shown, but any number of blue LEDs 80 a-80 n may be used dependingon the configuration requirements of discreet flexible pixel element 10and the operational capabilities of LED driver means as embodied by CCD100.

Referring now to FIG. 4-B, step-down switching regulator 120 is asolid-state IC device equipped with an internal 1.4 amp power switch(not shown) that performs step-down DC/DC conversion of on-board busvoltage (+VCC) to regulated DC output voltage as required to drive RGBLEDs 60-80 (+VLED). Step-down switching regulator 120 embodies aconventional DC/DC buck regulator topology as configured with inductor122 (L1), capacitor 124 (C3), Zener diode 126 a (CR1), and Schottkydiodes 126 b and 126 c (CR2-CR3). The use of a step-down switchingregulator in conventional DC/DC buck regulator DC voltage reduction iswell known and well understood in the art and the details of operationwill not be reexamined here in the interest of brevity.

In operation, step-down switching regulator 120 uses current mode, highfrequency switching to make and break the connection with inductor 122(L1) at location 120 a (SW). When step-down switching regulator 120internal power switch is ON, a voltage is forced across inductor 122(L1) due to the differential voltage at location 120 b, corresponding toVIN at connection L1-1 and +VLED at connection L1-2 of inductor 122(L1). Voltage across inductor 122 (L1) sets the bias states of diodes126 a-126 c (CR1-CR3) causing current to flow in inductor 122 (L1) andacross the load (RGB LEDs 60-80), charging capacitor 124 (C3), whichthereby modulates current change at inductor 122 (L1) presenting astable output voltage at +VLED. When step-down switching regulator 120internal power switch is OFF, voltage across inductor 122 (L1) isremoved causing it to discharge thereby maintaining current flow.Voltage is reversed across inductor 122 (L1) resetting the bias statesof diodes 126 a-126 c (CR1-CR3) causing capacitor 124 (C3) to dischargein combination with inductor 122 (L1), maintaining stable output voltageat +VLED at a value set by feedback resistor network 130 (R6-R7) inaccordance with the power requirements of RGB LEDs 60-80. Transientvoltage suppressor 128 embodies a resistor-capacitor network thatprovides over-voltage protection to the inputs and outputs of CCD 100.

In a preferred embodiment, step-down switching regulator 120 embodiesthe Linear Technology Corporation, 500 kHz Step-Down SwitchingRegulator, Model LT1936; the apparatus, processes, functions andcharacteristics of said preferred embodiment of step-down switchingregulator 120 as described in applications manual “LT1936 1.4A, 500 kHzStep-Down Switching Regulator (LT 1006 Rev. C, undated)” provide acomplete and detailed understanding of the application of said preferredembodiment and that document is hereby incorporated in its entirety byreference thereto.

Those skilled in the art will apprehend that the foregoing exposition,as well as other aspects and features of step-down switching regulator120 here unstated, including means and methods of IC device applicationand operational and functional details, are well known in the art.Notwithstanding, certain advantages obtain in the application ofstep-down switching regulator 120 as embodied by the presentinvention: 1) a large DC/DC step-down power change is effected with verylittle power dissipation resulting in high power density (W/in³) withindiscreet flexible pixel elements 10 enabling high component packingdensity resulting in a smaller overall package of discreet flexiblepixel element and higher apparent resolution of electronic displaydevices; 2) high frequency, constant-current PWM power regulation allowsfor use of fewer, smaller and less expensive collateral components whichgenerate less heat and eliminate any requirement for external cooling.

FIGS. 5-A and 5-B are a simplified circuit diagram depicting portions oftwo series-connected discreet flexible pixel elements 10 of the presentinvention. Each series-connected CCD 100 embodies internal shiftregister 140 and output control register 142 which drive three currentregulators 144 and corresponding LED drivers. The first series-connectedCCD 100 a of said first series-connected discreet flexible pixel element10 a operatively receives visual image data (not shown) from linecontroller 32 via input connector 14 instant at input data line DATAIN14 c into said internal shift register 140 a at a data transfer ratedetermined by input clock line CLKIN 14 b clock frequency byfirst-in/first-out (FIFO) transfer sequence. When said internal shiftregister 140 a of said first series-connected CCD 100 a is full, CCD 100a transfers the visual image data to the next series-connected discreetflexible pixel element 10 b via output connector 16 instant at outputdata line DATAOUT 16 c. The next series-connected discreet flexiblepixel element 10 b receives the visual image data transmitted from saidfirst series-connected discreet flexible pixel element 10 a via inputconnector 14 instant, where it is received by CCD 100 b at input dataline DATAIN 14 c instant into said internal shift register 140 b in thesame manner as just described. The process of data transmission ofvisual image data continues iteratively through to discreet flexiblepixel element 10 n terminus of flexible pixel string 20 (ref. FIG. 2)until display controller 40 has transmitted all requisite visual imagedata to internal shift registers 140 a-n of CCDs 100 a-n of flexiblepixel elements 10 a-10 n, respectively.

Display controller 40 thereinafter operatively transmits a latch signalat latch-in signal line LATIN 14 d via electronic interface 34 and linecontroller 32 to said first series-connected discreet flexible pixelelement 10 a, which transmits it to the next series-connected discreetflexible pixel element 10 b iteratively through to discreet flexiblepixel element 10 n terminus of flexible pixel string 20 causing visualimage data resident in internal shift registers 140 a-n of eachseries-connected CCDs 100 a-n, respectively, to transfer into outputcontrol registers 142 a-n in parallel operation.

Display controller 40 thereinafter operatively transmits anoutput-enable signal at output-enable signal line OEIN 14 e viaelectronic interface 34 and line controller 32 to said firstseries-connected discreet flexible pixel element 10 a, which transmitsit to the next series-connected discreet flexible pixel element 10 b,iteratively through to discreet flexible pixel element 10 n terminus offlexible pixel string 20, thereby to initiate operation of currentregulators 144 a-n which pass driving current through RGB LEDs 60-80 ofeach series-connected discreet flexible pixel element 10 a-10 n. Currentregulators 144 a-n of CCDs 100 a-n, respectively, of discreet pixelelements 10 a-10 n, respectively, use the visual image data in outputcontrol register 142 to control current level (intensity ofillumination) and duration of current flow (time of illumination)through RGB LEDs 60-80, thereby to produce visual display output andlighting effects from series-connected discreet flexible pixel elements10 a-10 n.

It shall be understood by those skilled in the art that the forgoingexposition of operation of series-connected discreet flexible pixelelements 10 are exemplary and not exclusionary. Further details andspecifics of the internal operation of CCD 100 of the preferredembodiment with regard to operating voltage, current range, clockfrequency, control signal requirements, shift register size, PWMapplication method, signal timing, and the like, are described inapplication documents previously cited and herewith incorporated byreference, and will not be repeated here in the interest of brevity.

Various modifications can be made to the present invention withoutdeparting from the apparent scope thereof.

PARTS LIST

-   10 discreet flexible pixel element-   11 printed circuit board-   12 case-   13 light-emitting elements-   14 input connector-   14 a input power line (+VCC IN)-   14 b CLKIN (clock in) line-   14 c DATAIN (data in) line-   14 d LATIN (latch in) line-   14 e OEIN (output enable in) line-   16 output connector-   16 a output power line (+VCC OUT)-   16 b CLKOUT (clock out) line-   16 c DATAOUT (data out) line-   16 d LATOUT (latch out) line-   16 e OEOUT (output enable out) line-   18 flexible cable-   20 flexible pixel string-   30 flexible string array-   32 line controller-   34 electronic interface-   40 display controller-   42 operating system-   44 output image translator-   46 pixel array configuration table-   50 display system-   60 red LEDs-   70 green LEDs-   80 blue LEDs-   100 constant-current driver (U1)-   110 series resistors (R2-R5)-   120 step-down switching regulator (U2)-   120 a location SW-   120 b location VIN-   122 inductor (L1)-   124 capacitor (C3)-   126 a Zener diode (CR3)-   126 b Schottky diode (CR2)-   126 c Schottky diode (CR1)-   128 transient voltage suppressor-   130 feedback resistor network-   140 shift register-   142 output control register-   144 current regulators

1. A discrete flexible pixel element device, comprising: a pixelelectronics assembly, comprising a printed circuit board (PCB) havingon-board pixel element electronics including at least one light-emittingpixel elements, at least one pixel element driver means for operativelydriving said light-emitting pixel elements and at least one drivercontrol means for operatively controlling said pixel element drivermeans; a power and signal distribution means for operativelydistributing operating power, image data and control signals to saidlight-emitting pixel elements, said pixel element driver means and saiddriver control means; at least one input flexible cable means having aninput power and signal conductor for distributing input operating power,image data and control signals to pixel electronics unit; and, at leastone output flexible cable means having an output power and signalconductor for distributing output operating power, image data andcontrol signals to a like discrete flexible pixel element device,wherein said discrete flexible pixel element device can be conjoinedinterchangeably in series-connection with a plurality of like discreteflexible pixel element devices, to embody a flexible pixel string. 2.The device of claim 1, wherein the pixel electronics assembly comprisessurface-mount technology and solid-state integrated-circuit technology.3. The device of claim 2, wherein the at least one light-emitting pixelelements, the at least one pixel element drivers and the at least onedriver control means are surface mount technology and solid-stateintegrated-circuit technology.
 4. The device of claim 1, wherein the atleast one light-emitting pixel is an LED and the at least one pixelelement driver is a constant-current LED driver.
 5. The device of claim1, wherein the pixel electronics assembly receives operating power froma common source power bus or rail.
 6. The device of claim 1, wherein thepixel electronics assembly comprises DC-to-DC step-down voltageconversion and current-limiting circuits.
 7. The device of claim 1,wherein said at least one light-emitting pixel elements comprise aplurality of light-emitting pixel elements of various colors.
 8. Thedevice of claim 7, wherein the plurality of light-emitting pixelelements of various colors comprise colored LEDs.
 9. The device of claim8, wherein the various colors are selected from among red, green, blue,cyan, magenta and yellow.
 10. The device of claim 9, wherein the atleast one pixel element driver means comprises a single on-boardmulti-channel 3-channel constant-current LED driver device withpulse-width-modulated (PWM) control means for driving per channel aplurality of red LEDs, per channel a plurality of green LEDs, and perchannel a plurality of blue LEDs.
 11. The device of claim 9, wherein theat least one pixel element driver means comprises two on-boardmulti-channel 3-channel constant-current LED driver devices withpulse-width-modulated (PWM) control means for driving per channel aplurality of red LEDs, per channel a plurality of green LEDs, perchannel a plurality of blue LEDs, per channel a plurality of cyan LEDs,per channel a plurality of magenta LEDs, and per channel a plurality ofyellow LEDs.
 12. The device of claim 8, wherein the at least one pixelelement driver means comprises a plurality of on-board multi-channelconstant-current LED driver devices for driving per channel a pluralityof light-emitting pixel elements of various colors.
 13. The device ofclaim 8, wherein the at least one pixel element driver means comprises asingle on-board plural-channel constant-current LED driver device fordriving per plural channel a plurality of light-emitting pixel elementsof various colors.
 14. The device of claim 1, wherein the input powerand signal conductor comprises at least one input power conductor and atleast four input signal conductors.
 15. The device of claim 1, whereinthe output power and signal conductors comprises at least one outputpower conductor and at least four output signal conductors.
 16. Theinput flexible cable means and output flexible cable means of claim 1,wherein said output flexible cable means of at least a first discreteflexible pixel element device and said input flexible cable means of atleast a second discrete flexible pixel element device may be operativelyand interchangeably conjoined in plural series-connection to embody aflexible pixel string.
 17. The power and signal distribution means ofclaim 1, comprising at least two discrete flexible pixel element devicesconjoined in series-connection by at least one input flexible cablemeans and at least one output flexible cable means.
 18. The power andsignal distribution means of claim 1, comprising at least two discreteflexible pixel element devices operatively conjoined inseries-connection having at least five power and signal conductors thatoperatively transmit operating power, image data and control signalsfrom a first discrete flexible pixel element device to a second discreteflexible pixel element device in series transmission thereof.
 19. Adiscrete flexible pixel element, comprising: a non-unique, non-addressedself-contained unit comprising a pixel electronics unit; a single inputflexible cable means; a single output flexible cable means; an inputflexible cable connector means having power and signal conductorterminals and fitment features to operatively to conjoin with an outputflexible cable connector means of a preceding upstream discrete flexiblepixel element in series-connection; an output flexible cable connectormeans having power and signal conductor terminal contacts and fitmentfeatures to operatively to conjoin with an input flexible cableconnector means of a following downstream discrete flexible pixelelement in series-connection; and, power and signal distribution meansoperatively to receive transmission of operating, power, image data andcontrol signals from a preceding upstream discrete flexible pixelelement in series-connection via said input flexible cable means andoperatively to transmit operating power, image data and control signalsto a following downstream discrete flexible pixel element inseries-connection via said output flexible cable means; wherein saiddiscrete flexible pixel element is fully interchangeable with any otherlike discrete flexible pixel element.